There was a lot of windows initialization code specific to the era that predates Windows Vista such as reading DNS configuration from the registry, and dynamically loading libraries to get access to functions that didn't exist in XP or earlier releases.
Vista was released in January 2007, and was EOL'd in 2017, and support for Vista is still maintained with this patch set.
XP was EOL'd in Apr 8 2014.
I believe the last OS based on something earlier than Vista was POSReady 2009, as it was XP based for some reason, and that was EOL'd in January 2019. Considering any POS system falls under the PCI-DSS rules, they aren't allow to run POSReady 2009 any more so there is no reason to try to continue supporting such systems.
We have also targeted with our build system Vista support for the last few years, and while developers could change the target, we haven't had any reports that they have.
Originally started by Daniel Stenberg (@bagder) with #123, this patch reorganizes the c-ares source tree to have a more modern layout. It also fixes out of tree builds for autotools, and automatically builds the tests if tests are enabled. All tests are passing which tests each of the supported build systems (autotools, cmake, nmake, mingw gmake). There may be some edge cases that will have to be caught later on for things I'm not aware of.
Fix By: Brad House (@bradh352)
The rc4 function iterates over a buffer of size buffer_len who's maximum
value is INT_MAX with a counter of type short that is not guaranteed to
have maximum size INT_MAX.
In circumstances where short is narrower than int and where buffer_len
is larger than the maximum value of a short, it may be possible to loop
infinitely as counter will overflow and never be greater than or equal
to buffer_len.
The solution is to make the comparison be between types of equal width.
This commit defines counter as an int.
Fix By: Fionn Fitzmaurice (@fionn)
Brad House
Fionn Fitzmaurice